Method of manufacturing liquid crystal display

• US 7,112,512 B2
• Filed: 06/15/2004
• Issued: 09/26/2006
• Est. Priority Date: 11/26/2003
• Status: Active Grant

• Current Assignee: HannStar Display Corporation
• Original Assignee: HannStar Display Corporation
• Inventors: Hung, Hung-Yi, Lan, Chih-Chieh
• Primary Examiner(s): Fammy, Wael
• Assistant Examiner(s): Ahmadi, Mohsen
• Application Number:
  US10/868,908
• Publication Number:
  US 20050112790A1
• Time in Patent Office: 833 Days
• Field of Search: 438/430, 438/149, 438/151, 438/158, 438/161, 438/30, 438/40, 438 42- 43, 257/57, 257/59, 349/122, 349/138, 349/42, 349/43, 349/46
• US Class Current: 438/430
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136236 using a grey or half tone lithographic process
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask

Abstract

On a substrate, the pattern of the first conductive layer is defined, that is, a gate line combination including gate pads, scanning lines and gate electrodes. A gate insulating layer, a semiconductor layer, a doped semiconductor layer and a second conductive layer are deposited on the substrate and the above-mentioned gate line combination in sequence. A photoresist layer is overlaid on the second conductive layer. The photoresist layer within the aperture areas is fully exposed. Using a half-tone mask or a slit pattern to make parts of the photoresist layer lying on the gate pads and the gate electrodes are not exposed to its full depth. As a result, the photoresist pattern formed varies in thickness. After being processed with drying etching and wet etching for several times, all the layers previously deposited within the aperture areas can be totally etched and removed. However, as regards the layers deposited on the gate pads and the gate electrodes, etching only takes place in those layers above the semiconductor layer. Then, an organic protection layer is laid on the substrate and the above-mentioned structure, and the holes, which are to function as the passageways for the transparent conductive layer to contact the metallic layer, are defined on the organic protection layer. Then, the gate pads are exposed out of holes above them, using dry etching again. Lastly, the pattern of the transparent conductive layer is defined on the organic protection layer and in the plurality of holes.

Claims

1. A method of manufacturing a liquid crystal display, comprising the steps of:

forming a first conductive layer on a substrate;

patterning the first conductive layer to form a gate line with a gate line, a gate electrode and a gate pad;

forming a gate insulating layer, a semiconductor layer, a doped semiconductor layer and a second conductive layer on the gate line;

forming a photoresist pattern with various thicknesses on the second conductive layer, wherein said photoresist pattern is a layer unexposed in a certain thickness over said gate pad and said gate electrode;

providing stepwise etching on said second conductive layer, said doped semiconductor layer, and a portion of said semiconductor layer so as to form a data line with source electrode and a drain electrode;

forming an organic protection layer,

patterning said organic protection layer to form a plurality of through holes; and

forming a third conductive layer in said through holes electrically connected to said second conductive layer.

2. The method of manufacturing a liquid crystal display of claim 1, wherein the photoresist pattern with various thicknesses is formed by a halftone mask.

3. The method of manufacturing a liquid crystal display of claim 1, wherein the photoresist pattern with various thicknesses is formed by a mask with a slit pattern.

4. The method of manufacturing a liquid crystal display of claim 1, wherein the organic protection layer is made from benzocyclobutene (BCB), perfluorocyclobutane (PFCB), fluorinated para-xylene, acrylic resin, or color resin.

5. The method of manufacturing a liquid crystal display of claim 1, wherein all areas are etched to the substrate to stop except the areas of the gate line and data line.

6. The method of manufacturing a liquid crystal display of claim 1, further comprising a step of forming an inorganic protection layer on the semiconductor layer over the gate electrode.

7. The method of manufacturing a liquid crystal display of claim 6, wherein the inorganic protection layer is formed by treating the semiconductor layer with a mixture of plasma and nitrogen, hot oxygen or hot nitrogen.

8. The method of manufacturing a liquid crystal display of claim 1, further comprising a step of removing the gate insulating layer and semiconductor layer disposed on the gate pads so as to expose the gate pads.

9. A method of manufacturing a liquid crystal display, comprising the steps of:

forming a first conductive layer on a substrate;

patterning the first conductive layer to form a gate line with a gate line, a gate electrode and a gate pad;

forming a gate insulating layer and a semiconductor layer on the gate line;

forming an etching stop layer on the semiconductor layer and over the gate electrode;

forming a doped semiconductor layer and a second conductive layer on the etching stop layer and semiconductor layer;

patterning the second conductive layer, doped semiconductor layer, semiconductor layer and gate insulating layer to form a data line with a source electrode and a drain electrode;

forming an organic protection layer;

patterning the organic protection layer so as to form a plurality of through holes;

forming a third conductive layer in the through holes electrically connected to the second conductive layer.

10. The method of manufacturing a liquid crystal display of claim 9, wherein the thickness of the etching stop layer is greater than the total thickness of the semiconductor layer and gate insulating layer.

11. The method of manufacturing a liquid crystal display of claim 9, further comprising a step of removing the gate insulating layer over the gate pad by a mask after the second conductive layer is patterned.

12. The method of manufacturing a liquid crystal display of claim 9, wherein the organic protection layer is made from benzocyclobutene (BCB), perfluorocyclobutane (PFCB), fluorinated para-xylene, acrylic resin, or color resin.

13. The method of manufacturing a liquid crystal display of claim 9, wherein all areas are etched to the substrate to stop except the areas of the gate line and data line.

14. A method of manufacturing a liquid crystal display, comprising the steps of:

forming a first conductive layer on a substrate;

patterning the first conductive layer to form a gate line with a gate line, a gate electrode and a gate pad;

forming a gate insulating layer on the gate line and patterning the gate insulating layer for the gate pad to be exposed;

forming a semiconductor layer, an etching stop layer, a doped semiconductor layer and a second conductive layer on the gate insulating layer and gate line;

patterning the second conductive layer, doped semiconductor layer and semiconductor layer to form a data line, a source electrode and a drain electrode;

forming an organic protection layer;

patterning the organic protection layer to form a plurality of through holes; and

forming a third conductive layer in the through holes electrically connected to the second conductive layer.

15. The method of manufacturing a liquid crystal display of claim 14, further comprising a step of removing the gate insulating layer except that over the gate line and data line after the gate insulating layer is formed.

16. The method of manufacturing a liquid crystal display of claim 14, wherein the gate line and gate electrode is covered with the gate insulating layer after the gate insulating layer is patterned.

17. The method of manufacturing a liquid crystal display of claim 14, wherein the organic protection layer is selected from a group consisting of benzocyclobutene (BCB), perfluorocyclobutane (PFCB), fluorinated para-xylene, acrylic resin, or color resin.